I use the Organ DB X 1 -100/16 I've quilted quite a few on my 1600P DBX and have no problems.I got a 100 pack(10/10s) a few years ago off of an Ebay store.I also use prewound bobbins off of an Ebay store.Let me know if you want the store's name.
Shelly
Ft.Lupton,CO